This class will take $_SERVER['HTTP_ACCEPT_LANGUAGE'] and convert it into a list of languages/locales. The returned array is sorted by preference with the highest preference first in the list.

use Ryantxr\BrowserPreferredLang\PreferredLang;
$p = new PreferredLang;
$langs = $p->get(['en', 'zh-cn', 'es'], $_SERVER['HTTP_ACCEPT_LANGUAGE']);
print_r($langs);

Output

(
    [en] => 0.8
    [es] => 0.4
    [zh-cn] => 0.3
)

Installing

composer require ryantxr/browser-preferred-lang